Would you go to the doctors?

My 8yo DS has a cold and cough and has now developed a pimply rash on face and body. He had similar a few years ago and I went to docs who said it was just caused by virus and didn't need treatment. He is OK in himself apart from usual cold/cough symptoms but my mum is panicking telling me I need to take him to the doctors. Would you take your DC with these symptoms?